When buying a metal detector consider the price. If the metal detector offers the best features of a then expect it to be expensive. If having fewer features is all right with you, go for a less expensive one. Metal detectors can run from as low as $50 to higher than $400.

Some metal detectors use BFO (Beat Frequent Oscillation). This technology contains two coils of wire. The two coils are represented by two wires which is the large and the small. The large coil can be found in the search coil of the detector while the small coil is found on the System Control Pack. The coils are connected to an oscillator which produces pulses of current. The pulse passes through the coils in order to generate radio waves.

A receiver within the System Control Pack receives the radio waves causing it to make a series of tones which is based upon the frequencies coming from the radio waves. Once the detector search coil encounters a coin or any metal item, it is surrounded by a magnetic field which causes interference with the frequency. The tone produced by the receiver is then changed. In choosing the best detectors, you should pick the ones with BFO. This technology is the easiest to use and the cheapest to own.

Metal detectors using PI (Pulse Induction) technology often makes use of a single coil or even a series of coils that works as a receiver and the transmitter. The short bursts of electricity are allowed to pass through a coil or wire which causes magnetism. The magnetic field will reverse its polarity if the bursts of electrical current are stopped.

More pulses are created when sharp electrical spike is created. Then the whole process will repeat and works like a series of echoes, giving it a different report which depends on the metal it has encountered. Therefore, this type of detector is not that ideal for discrimination between the various types of metals or coins. This is appropriate to use in areas where salt-water and metals can be detected.

VLF (Very Low Frequency) is a metal detector having two search coils. The two coils are the ?transmitter coil? which rapidly transmits electricity and the other coil known as the ?receiver coil?. The activity of this coil is implied in its name already. It is responsible for receiving frequencies that bounce back from the object that the coil detects. This type of detector is best for identifying different types of metals.

Now that you have learned the three different types of metal detector, it's up to you to make your choice as to what type of detector you wish to use for your searches.